Proposal for Coherent Coupling of Majorana Zero Modes and Superconducting Qubits Using the 4 pi-Josephson Effect

TL;DR

This paper proposes a method to couple Majorana zero modes with superconducting qubits via the 4 pi-Josephson effect, enabling topological quantum operations and memory with enhanced protection.

Contribution

It introduces a novel coupling scheme using an ancilla fluxonium qubit controlled by the 4 pi-Josephson effect for topological quantum computing.

Findings

Demonstrates sensitive detection of topological superconductivity

Shows how to measure Majorana qubit states

Proposes 2-qubit operations and topologically protected quantum memories

Abstract

We propose to use an ancilla fluxonium qubit to interact with a Majorana qubit hosted by a topological one-dimensional wire. The coupling is obtained using the Majorana qubit-controlled 4 pi Josephson effect to flux bias the fluxonium qubit. We demonstrate how this coupling can be used to sensitively identify the topological superconductivity, to measure the state of the Majorana qubit, to construct 2-qubit operations, and to implement quantum memories with the topological protection.